a) Field of the Invention
This invention relates to the field of folding hinges designed for use in conjunction with devices that use multiple poles or similar means and where it is desirable to easily erect and collapse the same. More specifically, this device is used in conjunction with crutches where the user typically has an injury, is handicapped or otherwise physically challenged; and as such, would desire the convenience of a single hand operation. The device is also applicable with walkers, golf bag carriages, baby carriages, and similar devices. This invention consists of a plurality of self locking hinges connected via a connection means and a linked release mechanism that provides a means to engage and disengage the invention using only a single hand making use of multiple poled and related devices convenient. Presently there is no effective single release multiple poled hinged device in the market place. The present invention fills such a void.
b) Description of the Related Art
The present invention is directed towards folding or collapsible hinges that are designed for use in conjunction with multiple poled or similar devices. The present invention consists of several self locking hinges connected to each other so that a multiple hinged device is created. Presently, there are different folding hinge designs that can be used in conjunction with a single pole or other device to create collapsible frames. However, none of the prior art has a means of connecting two or more hinges in a poled device to make an effective collapsing hinged device. But more critically, none of the prior art, individually or collectively, incorporates all of the novel aspects of the present invention of a simple, inexpensive, yet easy to manufacture, strong self locking set of hinges that can be operated with merely a single hand.
The prior art has several different collapsible hinge designs but those designs have a limitation in that the hinge is designed to work solely as an independent hinge. A common collapsible hinge assembly in the prior art uses spring loaded poles that facilitate both the opening of the hinge assembly and the maintaining of the hinge assembly in a closed position. Some devices do not use an actual hinge at the connection point but rely on the spring loaded, or bungee cord loaded, poles and a sleeve type arrangement where one pole possess a sleeve designed to slide over a second pole. This arrangement is common with poles used to support pop up camping tents and other similar devices. The main draw back is that two hands are required to assemble the two sections of the pole due to the combination of the internal spring mechanism and the overlapping sleeve arrangement. Other devices have an internal spring loaded means, but have many internal parts that make is complicated and costly to manufacture. The hinged portions of the present invention only have three basic parts and are easily manufactured and placed inside a pole without any internal components.
Other devices do not use springs or sleeves, such as U.S. Pat. No. 3,833,964, but use the pole material to create the spring action. This device fails from the shortcoming of not yielding a true end-to-end 180-degree connection desirable for crutch, walker or other devices. Furthermore, this hinge device could be disengaged if one where to apply force to underside of the hinge, a concept not desirable for crutches or walkers. Still other devices utilize a latch mechanism as the present invention. One such example is U.S. Pat. No. 96,777, a device specifically designed for use with an umbrella. This device does not create a straight 180-degree orientation and does not easily collapse down for easy storage. Further, it does not have an offset hinge connection as the present invention preventing the device from being collapsed to a compact sized for easy transport and storage.
Some devices possess an offset hinge pivot connection. An example can be seen in U.S. Pat. No. 5,685,660 and its cited prior art references contained within the patent. All of these references suffer from the common problems of not being able to be engaged or disengaged with a single hand. The cited reference itself does have a push button to release the mechanism but in doing so one's own finger will be holding the press plate of the opposite hinge portion preventing the same from disengaging from the main hinge portion, thereby preventing the device from being a single hand operation. Other devices require an external means to disengage the hinge, for example Cheng, U.S. Pat. No. 5,970,540. The Cheng hinge design can not operated on its own as a self standing hinge but must be incorporated with non hinge elements for it to be operated. To disengage the hinge in the Cheng reference one must hold onto the playpen with one hand while grabbing the floor of the playpen with the other. Lastly and most critically, all of the abovementioned devices are not designed as multiple hinged assemblies.
In sum, the present invention overcomes all the shortcomings of the prior art and discloses a simple self locking hinge assembly. The design is simple to manufacture, can come in a variety of shapes and sizes given the application requirements and has few parts making it cost effect. Due to the unique geometry of its elements and their respective geometric orientation the hinge assembly can be easily opened and closed with a single hand. Neither the unique geometry of the hinge's elements or their respective geometric orientation is seen in the prior art. When closed the hinge assemble creates a strong connection between a multiple of hinges and the respective poles that the hinges are attached. Furthermore, the device has an ingenious means of axially connecting several hinges together so that the hinges can work in unison in a multiple poled device while at the same time not compromising it's single hand operation, neither concept seen in the prior art. Lastly, the invention provides additional lateral strength and stability to a multiple poled device.